I. Field
The present invention relates generally to data communication, and more specifically to techniques for testing a wireless link using configurable channels and rates.
II. Background
Wireless communication systems such as code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, and others are widely deployed to provide various types of services such as voice, packet data, and so on. For these systems, it is highly desirable to utilize the available resources as efficiently as possible. This typically entails transmitting as much data to as many users within as short a time period as supported by the conditions of the wireless links.
To achieve the above goal, the wireless links between the base stations and terminals within the system may be characterized. Based on the characterized link conditions, the system may be better able to (1) select a particular set of terminals to serve, (2) allocate a portion of the available resources (e.g., transmit power) to each selected terminal, and (3) transmit to each selected terminal at a data rate deemed to be supported by the allocated transmit power and characterized link conditions.
Conventionally, a wireless link is characterized by transmitting a known data pattern (e.g., generated by a pseudo-random number generator), receiving the transmitted data pattern, comparing the received data pattern with a locally generated data pattern to determine transmission errors, and reporting the results back to the transmitter. This “loop-back” testing is typically performed continuously for a number of frames over a desired test interval. The test results would then be reflective of the performance of the wireless link over that test interval.
Many newer generation wireless communication systems are capable of flexible operation. For example, voice data may be transmitted in a non-continuous manner (depending on the amount of speech activity) and over one or multiple (e.g., transport) channels, the rate may be allowed to vary from frame to frame, the processing of the data may also vary (e.g., from frame to frame and/or from channel to channel), and so on. The conventional loop-back test technique typically characterizes the wireless link for one channel based on a set of test parameters. This conventional test technique may not provide an accurate assessment of the performance of the wireless link when the system operates in this flexible manner.
There is therefore a need in the art for techniques that can characterize a wireless link under various flexible operating conditions supported by a wireless communication system.